Calculate and write the answer using scientific notation: If one star is counted every second Class 8

Calculate and write the answer using scientific notation: If one star is counted every second Class 8

Question 1.

Calculate and write the answer using scientific notation: If one star is counted every second, how long would it take to count Class 8

(i) If one star is counted every second, how long would it take to count all the stars in the universe? Answer in terms of the number of seconds using scientific notation.

(ii) If one could drink a glass of water (200 ml) every 10 seconds, how long would it take to finish the entire volume of water on Earth?

Solution:

(i) 2 × 10²³ seconds.

(ii) 2 × 10²⁵ × 16 mL = Total water.

So, required time

= [latex]\frac{2 \times 10^{25} \times 16 \times 10}{200}[/latex] Seconds

= 16 × 10²³ × 10 seconds

= 16 × 10²⁴ seconds

= 1.6 × 10²⁵

seconds